mid-ocean ridge- the largest chain of mountains in the world
sonar- a device that bounces sound waves off under water objects and then records the echoes o these sound waves
sea-floor spreading- the process that continually adds new material to the ocean floor
deep-ocean trenches- deep under water canyons
subduction- the process by which the ocean trench and back into the mantle
Outline
T= Sea Floor Spreading
Summary
-East Pacific Rise strange creatures
-provided evidence for theory of continental drift
Mapping the Mid-Ocean Ridge
-longest chain of mountains
-curve into ocean, most mountains under water
-mapped it by using sonar
Evidence for Sea-Floor Spreading
-ocean floor moves like conveyor belt carrying continents with them
-At mid-ocean ridge molten material rises from mantle/erupts
-spreads out pushing older material to both sides of ridge
-Hess called continually add new material to ocean floor sea-floor spreading
-evidence from molten material
-four kilometers in ocean floor pillow shaped rocks
-only forms when molten material hardens after erupting under water
-evidence from magnetic stripes
-Earth's magnetic poles reversed themselves 780,000 years ago
-rocks in ocean floor lies in pattern of magnetized stripes
Vocabulary
mid-ocean ridge- the largest chain of mountains in the world
sonar- a device that bounces sound waves off under water objects and then records the echoes o these sound waves
sea-floor spreading- the process that continually adds new material to the ocean floor
deep-ocean trenches- deep under water canyons
subduction- the process by which the ocean trench and back into the mantle
Outline
T= Sea Floor Spreading
Summary
-East Pacific Rise strange creatures
-provided evidence for theory of continental drift
Mapping the Mid-Ocean Ridge
-longest chain of mountains
-curve into ocean, most mountains under water
-mapped it by using sonar
Evidence for Sea-Floor Spreading
-ocean floor moves like conveyor belt carrying continents with them
-At mid-ocean ridge molten material rises from mantle/erupts
-spreads out pushing older material to both sides of ridge
-Hess called continually add new material to ocean floor sea-floor spreading
-evidence from molten material
-four kilometers in ocean floor pillow shaped rocks
-only forms when molten material hardens after erupting under water
-evidence from magnetic stripes
-Earth's magnetic poles reversed themselves 780,000 years ago
-rocks in ocean floor lies in pattern of magnetized stripes